A major source of chronic low back pain is discogenic pain, which is also known as internal disc disruption. Patients suffering from discogenic pain tend to be young (30-50 years of age), otherwise healthy individuals who present with pain localized to the back. Usually discogenic pain occurs at the discs located at the L4-L5 or L5-S1 junctions. Pain tends to be exacerbated when patients put their lumbar spines into flexion (i.e. by sitting or bending forward) and relieved when they put their lumbar spines into extension (i.e. arching backwards). Discogenic pain can be quite disabling, and for some patients it dramatically affects their ability to work and otherwise enjoy their lives.
Current treatment alternatives for patients diagnosed with chronic discogenic pain are quite limited. Many patients continue with conservative treatment (examples include physical therapy, massage, anti-inflammatory and analgesic medications, muscle relaxants, and epidural steroid injections) and live with a significant degree of pain. Others elect to undergo spinal fusion surgery, which typically involves discectomy (removal of the disk) together with fusion of adjacent vertebrae. Fusion is not typically recommended for discogenic pain because it is irreversible, costly, associated with high morbidity, and of questionable effectiveness. Despite its drawbacks, however, spinal fusion for discogenic pain remains common due to the lack of viable alternatives.